An experimental treatment for Covid-19 championed by President Donald Trump — in which patients are given doses of hydroxychloroquine, a drug used to treat malaria and lupus, along with the antibiotic azithromycin — raises the risk for some patients of dangerous irregular heartbeats that could be fatal, cardiologists warn in new guidance published by the American College of Cardiology.

According to the lead author of the paper, Dr. Eric Stecker, an associate professor of cardiovascular medicine at Oregon Health & Science University, any patients treated with the combination therapy should be monitored for ventricular arrhythmia, the irregular beating of the heart’s lower chambers, which can lead to cardiac arrest. “We don’t know the magnitude of the risk,” Stecker said in an interview on Sunday, but both drugs can raise the odds of irregular heartbeats for some patients, and the risk is greater when they are taken together.

The president has repeatedly dismissed warnings from Dr. Anthony Fauci, the nation’s top infectious disease expert, that the drugs might not be as safe or effective for people infected with the new coronavirus as they are for other illnesses. On Saturday, at a White House briefing on the global pandemic, Trump urged Americans to try hydroxychloroquine and suggested that people infected with the virus had nothing to lose by taking it, as long as their doctors agree.

When the president did mention that people with heart conditions might need to forgo the combination therapy, he wrongly suggested that the only risk to them was from azithromycin, not hydroxychloroquine.

Adding to the danger, Stecker said, is the fact that many people don’t know that they have the underlying heart issue that predisposes them to dangerous heart rhythms. That means that they could be at risk of drug-induced heart failure if they are treated for Covid-19 with hydroxychloroquine, which is marketed as Plaquenil. The potential adverse effects of Plaquenil listed on the FDA’s website include life-threatening or fatal heart failure, which has also been reported with chloroquine, from which hydroxychloroquine is derived.

During the briefing on Saturday, Trump also suggested that he might take hydroxychloroquine himself based on what he called first “a rumor” and then “a study” which, he claimed, indicated that lupus patients taking the drug are not contracting Covid-19. That, however, is entirely false, according to Dr. Jinoos Yazdany, a rheumatologist at University of California, San Francisco.

“People with lupus, including those on hydroxychloroquine, have gotten Covid-19,” Yazdany told me via Twitter, pointing to data gathered by the Global Rheumatology Alliance. That group’s registry has compiled information on 167 people with rheumatological conditions, including lupus, who had contracted Covid-19 as of Friday. More than 25 percent of the patients in the registry who became infected with Covid-19 were on hydroxychloroquine at the time of diagnosis.

“Based on early data currently available in our registry, we are not able to report any evidence of a protective effect from hydroxychloroquine against Covid-19,” the alliance said in a statement.

“Antimalarial drugs can cause ventricular arrhythmias, QT prolongation, and other cardiac toxicity, which may pose particular risk to critically ill persons,” Yazdany and her colleague Dr. Alfred Kim wrote in The Annals of Internal Medicine last week. “Given these serious potential adverse effects, the hasty and inappropriate interpretation of the literature by public leaders has potential to do serious harm.”

“A randomized, controlled trial would be the only way to study this to get a reliable answer to this question,” Yazdany and Kim concluded.

On Friday, questions about a small French trial of the drug treatment that Trump and his defenders have relied on were endorsed by the publishers of the International Journal of Antimicrobial Agents, where the research was submitted. The board of the International Society of Antimicrobial Chemotherapy, which publishes the journal, said in a statement that it “shares the concerns regarding” the article in which the encouraging results were reported. “The ISAC Board believes the article does not meet the Society’s expected standard, especially relating to the lack of better explanations of the inclusion criteria and the triage of patients to ensure patient safety,” the statement said.

Trump’s repeated, impassioned advocacy for hydroxychloroquine has created a global run on the medication, driving up prices and making it difficult for patients with lupus and rheumatoid arthritis to fill their prescriptions. It also led some observers to wonder whether or not the president, who still refuses to release his tax returns, might have some sort of a financial interest in promoting the drug.

“One of the problems with knowing very little about the Trump family’s finances,” the New York Times columnist Jamelle Bouie wrote, “is when the president gets fixated on something like hydroxychloroquine, we don’t know if it reflects his obsession with quick fixes and miracle cures or if he’s trying to juice an investment.”

The New York Times reported on Monday that Trump does have “a small personal financial interest in Sanofi, the French drugmaker that makes Plaquenil, the brand-name version of hydroxychloroquine.” In a financial disclosure released last year, the president listed among his assets three family trusts that invested in a Dodge & Cox mutual fund, which had shares of Sanofi as its largest holding.

Another possible motivation for Trump’s sales pitch about the drug is that he is doing something he has done in the past: staking out a position on an issue of national interest and gambling that he has picked the right side. That way, if the drug treatment proves to be effective, he can claim credit. If it proves ineffective, he will simply change the subject of act as if he never advocated it in the first place. He did precisely this with the U.S. military intervention in Libya. In 2011, he loudly called for it on his “Apprentice” YouTube channel. Then, after the country deteriorated in the aftermath, he denounced Hillary Clinton for the intervention during the 2016 campaign and his company removed his video from YouTube.

On Saturday, Trump brushed off the need for data from clinical trials, immediately after his most senior medical adviser, Fauci, said that there was as yet no evidence that lupus patients taking hydroxychloroquine were protected from Covid infection.

Anyone wondering where Trump is getting his information can turn to a likely suspect: Fox News. Since the president started promoting hydroxychloroquine as a potential “gift from heaven,” his favorite network has relentlessly promoted anecdotal evidence that the drug could help Covid-19 patients and downplayed the need for clinical trials.

An analysis by Media Matters last week found that Fox News “personalities and guests promoted the use of the drugs over 100 times from March 23 through 25.”

The network gave particularly uncritical, positive coverage to claims by Dr. Vladimir Zelenko, a Trump supporter who has used the combination therapy to treat members of the Hasidic Jewish community in a village north of Manhattan.

On Friday night, Dr. Ramin Oskoui, a cardiologist, mistakenly claimed that “we’re not seeing patients with lupus who take Plaquenil, the branded name for hydroxychloroquine, we’re not seeing these individuals develop Covid. I’m not aware of any reported cases.”

Until randomized controlled trials can be completed, doctors can only guess whether or not hydroxychloroquine might be an effective antiviral medication against the new coronavirus that causes Covid-19. The handful of small, non-randomized trials that have been done so far have produced contradictory results, but Trump’s intense advocacy for the antimalarial drug as a potential “game-changer” has deeply politicized the public conversation over the treatment.

While Oskoui tells Fox News viewers that he thinks the drug is promising, and Fox hosts like Laura Ingraham taunt Fauci over every anecdotal sign that the treatment might work, many doctors agree with Fauci that there just is not enough evidence to support the president’s wager that it will work and worry about the possible side effects.

“The ongoing research is “somewhat encouraging but it is very preliminary,” Eric Stecker, the Oregon cardiologist, told me. “The level of evidence is too thin to really confidently say it is going to help people.”

“Whether hydroxychloroquine works in vivo is not proven for any virus, and in fact in randomized controlled trials against a number of viruses, including influenza, it doesn’t work at all,” Dr. Douglas Richman, a virologist and infectious disease specialist at the University of California, San Diego told The Lancet, a leading medical journal, last week. “It’s my personal prejudice that this is also going to be the case with coronavirus,” Richman added.

On Sunday, Fox News continued to back the medical advice dispensed by the president by giving air time to his lawyer, Rudy Giuliani, who attacked public health officials “in an ivory tower” who want evidence that hydroxychloroquine is safe and effective for patients infected with Covid-19. Displaying his level of ignorance with the science, Giuliani began with the false claim that hydroxychloroquine has side effects, “none of which are death.”

He went on to argue that there was no reason to wait for clinical trials to decide whether or not to use the drug against Covid-19. The choice of whether or not to try the untested drug on patients infected with the coronavirus, Giuliani insisted, “should be given to doctors, not to the bureaucrat in Washington, who want to go through three blind tests. When we finish the three blind tests, you know, most of America could be gone.”

Later on Sunday, when Jeremy Diamond of CNN challenged Trump about why he was giving medical advice at all — “Why not just let the science speak for itself? Why are you promoting this drug?” Diamond asked — Trump echoed Giuliani’s anti-science argument. “We don’t have time to go and say, ‘Gee, let’s take a couple of years and test it out, and let’s go and test with the test tubes and the laboratories,'” Trump said — completely misunderstanding that clinical trials on patients (known as “in vivo” testing) are not conducted in laboratory test tubes (known as “in vitro”). “We don’t have time, I’d love to do that, but we have people dying today,” Trump said.

When Diamond asked Fauci to weigh in on the issue of hydroxychloroquine — following a report that Trump’s belligerent trade adviser, Peter Navarro, had heatedly confronted the doctor about his refusal to endorse the untested treatment on Saturday — the president stepped forward and refused to let the medical expert answer the question.

After Trump said that the government had now purchased 29 million doses of hydroxychloroquine, he became enraged at an Associated Press reporter who asked him about evidence uncovered by the news agency that federal agencies had waited until mid-March to begin placing bulk orders of N95 respirator masks, ventilators and other medical equipment needed by health care workers. Trump interrupted to scold the questioner that the federal government had “done an unbelievable job.”

“The people that you’re looking at — FEMA, the military — what they’ve done is a miracle. What they’ve done is a miracle, in getting all of this stuff. What they’ve done for states is incredible, and you should be thanking them for what they’ve done, not always asking wise-guy questions,” Trump said, before calling an abrupt end to the briefing. He then stormed out, having lost control of what he had apparently expected would an entirely self-promotional event in the guise of a briefing on the public health emergency.

On Monday, the Fox host Dana Perino was upbraided by Dr. William Haseltine, a former professor at Harvard Medical School who helped develop the first treatment for HIV/AIDS, for claiming that some Covid-19 patients has experienced a “Lazurus-effect by using this drug.”

“That is nonsense, complete and utter nonsense,” Haseltine said. “There are always going to be people who promote one kind of quack cure or another and there are ‘Lazurus effects.’ In every epidemic I’ve looked at, it’s always the case.”

Last Updated: Monday, April 6, 11:50 p.m. EDT
This article was updated to report that Donald Trump does have a financial interest in sales of the drug hydroxychloroquine and to report new concerns about the methods of researchers in France who have reported positive results from a small, preliminary trial of the drug. Video was also added from Fox News, showing hosts repeatedly touting the drug as a Covid-19 treatment, and an interview with a skeptic of the treatment, Dr. William Haseltine, on Monday.